Steam-boiler smoke box



y 1930- G. B. ASHWORTH STEAM BOILER SMOKE BOX Filed Jan. 14, 1928 Patented May 27, 1930 UNIT s'rrss PAT' Heated STEAM-BOILER 'sMoKn Box AppIieation filed January 14, 1928. ser al No. 246,726.

This invention relates, generally, to smoke boxes of steam boiler, and, more particularly to those of locomotive boilers. The object of the invention .is to provide an appliance which, structurally, will be simple and inexpensive; will be low in maintenance cost; and which, in operation, will be absolutely air tight.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawing: Figure 1 is a side view, partly in section, of the forward portion of a locomotive smoke box, il-

lustrating an embodiment of the invention; Fig. 2, a front view of the same; Figs. 3, 4

and 5, partial transverse sections, on the lines a a, b b, and 0 0, respectively, of Fig. 2; and,

Fig. 6, a similarly taken section, on an enlarged scale, illustrating the form of the joint between the smoke box front and door.

In the practice of the invention, referring descriptively to the specific embodiment thereof which is herein exemplified, the shell 1, of the smoke box, is of ordinary substantially cylindrical form, its rear end being adapted for connection, as usual, to the front end of the boiler shell, and its forward end being closed by an annular front, 2, secured permanently to it by rivets 2 and a door,

3, hinged to the front. The inner diameter of the front, 2, is sufiiciently great to admit of the insertion and withdrawal, when de sired, of the superheater units of the boiler, and the spark arresting appliances.

The door, 3, is, in the operation of the boiler, connected to the front by a plurality of detachable buttons, 4, which clamp the front and door tightly together, when drawn to a bearing thereon by bolts, 4 and is adapted to be swung open, when desired, by being hinged to the front. The hinge connection complises a hinge plate, 5, secured to the door by rivets or bolts, 5, and having lugs, 5 which are coupled to lugs, 2 on the front, 2, r by hinge pins, 5.

In order to efiect a perfectly air tight joint between the door and the front, a bevelled or inclined seat, 2 is formed on the outer side of the front, 2, and a curved or inclined face, 3 formed on the rim of the door, abuts,

metal to metal, on said seat, as clearly shown in Fig. 6.- I

For the purpose of accommodatingwthe conditions presented in locomotive designs in which the air brake pumps are located in front, lateral recesses,-or depressions, 6, may be provided in the shell, 1, of the smoke box,

adjacent to the front thereof. In the instance illustrated, said recesses are formed in inwardly concaved or depressed plates, 6, connected to the wall, over openings therein, adjoining its front, by rivets, 6 but it will be obvious that, if preferred, said separate plates may be dispensed with, and the wall itself be correspondingly inwardly depressed.

The simplicity and economy of the inven- 'tion will be obvious to those skilled in the 'art, in the elimination of a ring connecting member and plastic gasket between the same and the smoke box front, which gasket member must be renewed each time the hinged type of front is opened, these'members characterizing the hinged type of front of present practice. The provision of a door of sufficiently large diameter to permit the insertion or removal of the superheater units and spark arresting members, materially promotes saving of time and expense in effecting renewals or repairs, and the oint between the smoke box front and the door is one that can maintained thoroughly air directed toward the box provided with'a v sealing face engaging the sealing face of the annular front, one of said faces being formed frusto-conical and the other face being curved in cross section providing thereby substantially line contact between the faces; and pressure adjustable clamping means for forcing the faces together in sealing relation whereby the pressure exerts a contracting force against said flange tending to producea wedge fit between the inclined and curved engaging surfaces.

2. In a steam boiler, the combination of a smoke box having an annular front projecting inwardly provided with a sealing face about its inner margin of frusto-conical formation; a closure for the front of the box having a marginal flange directed toward the box provided with a sealing face curved in cross section engaging the sealing face of the annular front, providing thereby substantially line contact between the faces; and

pressure adjustable clamping means for forc ing the faces together .in sealing relation whereby the pressure exerts a contracting force against said flange tend ng to produce a wedge fit between the inclined and curved engaging surfaces.

3. In a steam boiler, the combination of a smoke box having an annular front projectc ing inwardly provided with a sealing face about its inner margin; a closure for the front of the box having a margin directed toward the box provided with a sealing face engaging the sealing face of the annular front, one of said faces being formed frustoconical and the other face being curved in cross section, providing thereby substantially line contact between the faces; a hinge connecting the closure and thebox whereby the closure may be supported and swung to its seating position to maintain uniform relation between the opposed parts of the engaging surfaces; and pressure adjustable clamping means for forcing the faces together in sealing relation.

GEORGE B. ASHWORTH. 

